Surface heater arrangement



1965 w. w. KEUSDER ETAL 3,223,079

SURFACE HEATER ARRANGEMENT '7 Sheets-Sheet 1 Filed June 27, 1963 WA L722 14/ kzusozi/e uao RACHEL/ GMV J. PA wvz BY //V van-0E5 A77'ORNEY Dec. 14, 1965 w. w. KEUSDER ETAL 3,223,079

SURFACE HEATER ARRANGEMENT Filed June 27, 1963 7 Sheets-Sheet 2 WALTER 14 kEUSDE/Z ueo feA CHEL/ INVENTORS 1965 w. w. KEUSDER ETAL 3,

SURFACE HEATER ARRANGEMENT 7 Sheets-Sheet 3 Filed June 27, 1963 WALTER W. kgueoa? MG 0 RACHEL/ Gav J DA Y/VE INVENTOR5 BY 09/ (Z? A 7TO/?N/ 1965 w. w. KEUSDER ETAL 3,

SURFACE HEATER ARRANGEMENT 7 Sheets-Sheet 4 Filed June 27, 1963 WALTE/e 14/. KEusBDER ueo PACHEL/ GM V J. PA y/va INVENTORS A7TORNEY 1965 w. w. KEUSDER ETAL 3,223,079

SURFACE HEATER ARRANGEMENT Filed June 27, 1963 7 Sheets-Sheet 5 WALTER M4 A zusam 060 2A CHEL eu y J PA v/vz Dec. 14, 1965 w. w. KEUSDER ETAL 3,223,079

SURFACE HEATER ARRANGEMENT Filed June 27, 1963 '7 Sheets-Sheet 6 INVENTORS WALTER W. /(EL/.$DE/ liq. 15 4/60 /?A 0/15;

ea v J. PA y/va 1965 w. w. KEUSDER ETAL 3,223,079

SURFACE HEATEB ARRANGEMENT '7 SheetsSheet 7 Filed June 27, 1963 WALTE/e W /(L/5DE/ [/60 PA CHEL G u v 1 PA y/vz INVENTOR5 A77'OR/VEY United States Patent 3,223,079 SURFACE HEATER ARRANGEMENT Walter Wayne Keusder, 6420 Hedding St., Los Angeles,

Calif., and Ugo Racheli, Anaheim, and Guy J. Payne,

Los Angeles, Calif.; said Racheli and said Payne assignors to said Keusder Filed June 27, 1963, Ser. No. 291,110 22 Claims. (Cl. 126-2711) This invention relates to the surface heater art and more particularly to an improved arrangement for sequentially heating preselected areas of a specified surface.

In many applications such as road construction, weed burning, paint burning and the like it is often necessary as part of the over-all process involved to heat sequentially preselected surface areas. In road construction operation, particularly, such as the construction of asphalt pavement roadways having a surface layer of asphalt concrete, it is necessary in many of the construction and maintenance operations associated therewith to provide heat over extended areas of the roadway surface. For example, in many maintenance operations on asphalt pavement roadways it is necessary to heat the asphalt concrete layer prior to such steps as scarification, treatment with various additives, overlaying with new asphalt concrete, softening for removal, and the like. Such areas are generally heated by a mobile surface heater pulled by a tractor, or, alternatively, incorporated in a self-propelled vehicle moving at a preselected rate over the particular roadway to be heated. The hood in which the heating thermal energy is generated comprises an open bottom cavity in which fuel and air are combusted to provide the desired temperature. The open bottom of the cavity faces the roadway and di rect radiation from the products of combustion as well as thermal energy radiated and convected from the heated interior of the burner cavity is directed onto the asphalt concrete surface layer. This application of heat, for example, may soften the asphalt concrete layer to a sufficient degree to allow hot scarification or removal thereof.

In these operations it has often been found desirable to provide a hood that may be raised and lowered with respect to the surface to be heated. This permits traverse not only of irregular and rough ground, but also permits raising the entire hood structure to a sufficent height that will permit ready roadability when the burner is not in operation as, for example, when transporting the surface heater from one locale to another.

Further, it has been found desirable to have a hood that may be expanded and contracted in a direction perpendicular to the direction of traverse of the hood over the roadway to allow for the heating of wide or narrow areas in a single traverse by the surface heater, depending upon the design of the particular area to be heated.

Since the size of traffic lanes on different roadways varies, depending upon the particular road, a hood that may be expanded and contracted to account for the various widths of lanes often provides more economic operation by reducing the number of traverses by the surface heater necessary to heat a given section of roadway. A machine having such an expandable hood capability is also desirable in many other operations. For example, one surface heater with an expandable hood may be utilized in heating a narrow lane on a given roadway while in a contracted position and also utilized in heating large areas such as parking lots, airport areas and the like when the hood is expanded, thus providing a greater amount of surface area heated for a given traverse by the surface heater.

In many applications it is desirable to be able to shift the entire hood, in either an expanded or contracted condition, laterally of the direction of traverse of the surface 3,223,079 Patented Dec. 14, 1965 heater along the roadway so that the heat may be directed along preselected segments of the roadway with respect to the direction of traverse. This condition often occurs when heating roadways that include offsets, concrete structures, flammable areas and the like, and it is desirable to shift the hood laterally to avoid heating the areas associated with such areas not to be heated. Also, when turning corners on a curbed roadway that is being heated, it is necessary, in most applications, to shift the hood sideways, toward the curb, so that the entire surface area may be heated during one traverse while rounding the corner.

It has also been found desirable in many applications to be able to tilt the hood to accommodate crowned or other non-level areas. Thus, it is desirable that the hood have the capability of being rotated about a horizontal axis substantially parallel to the direction of traverse. Thus, crowned roads may be maintained at a substantially uniform distance from the hood.

Surface heaters for roadways and the like utilized in the past have not always been able to provide the above desiderata. For example, certain of the surface heaters utilized have incorporated a hood that could be raised and lowered and, to some extent, shifted laterally, but such hoods have generally been suspended by chains or other flexible members that resulted in undesirable oscillations of the hood during operation and the hood was not tiltable or laterally expandable. Other prior surface heaters have incorporated hoods that are comparatively fixed with regard to lateral movement and none, as far as applicants are aware, have been expandable to allow uniform heating over varying widths laterally of the direction of traverse.

While, for convenience, the description of applicants invention herein is in terms of an asphalt roadway surface heater, it will be understood that the same problems are often involved in weed burning and paint removal, soil drying and other similar arrangements. Therefore, while the description herein of the preferred embodiments of applicants invention describes applicants invention as being utilized in an asphalt pavement roadway surface heater, it will be apparent that applicants invention can well be utilized in many other surface heating applications.

Accordingly, it is an object of applicants invention to provide an improved surface heater arrangement.

It is another object of applicants invention to provide an improved mobile surface heater arrangement.

It is yet another object of applicants invention to provide a surface heater arrangement in which the hood may be expanded and contracted to provide an increase and decrease in the volume of the hood burner cavity to provide corresponding changes in the size of the area of the surface that is heated by one traverse of the surface heater.

It is another object of applicants invention to provide a surface heater having an expandable hood that may be shifted laterally of the direction of traverse of the surface heater.

It is yet another object of applicants invention to provide a surface heater arrangement in which an expandable hood may be shifted laterally, raised and lowered with respect to the surface that is to be heated.

It is another object of applicants invention to provide a surface heater arrangement in which the hood may be pivoted or tilted about a horizontal axis.

These objects and the above desiderata are achieved, according to one aspect of applicants invention by providing a mobile vehicle adapted to be moved over surface structures to be heated. The mobile vehicle comprise a wheeled vehicle having a substantially horizontally-dis- 3 posed stationary frame member spaced a preselected distance above the surface area, such as an asphalt pavement roadway, that is to be heated. An intermediate frame member is position-ed underneath the stationary frame member and is movably coupled to the stationary frame member by a;plurality of articulated bell crank means.

In this embodiment one articulated bell crank is provided on the stationary frame above each of the forward corners of the intermediate frame and pivotally coupled thereto. A separate hydraulic actuator is coupled to the stationary frame and to each of the articulated bell crank members. Torque tubes, supported in bearings 'coupled to the stationary frame connect each of the two articulated bell cranks to a linkage pivotally coupled to each of the rear corners of the intermediate frame. Simultaneous actuation of the hydraulic actuators 'raises and lowers the intermediate frame maintaining it substantially parallel to the stationary frame. Independent actuation of either of the two hydraulic actuators raises or lowers one side or the other of the intermediate frame, thereby tilting the intermediate frame about a horizontal axis substantially parallel to the direction of traverse of the surface heater.

An expandable hood is slidably supported from the lower side of the intermediate frame. "In this embodiment the expandable hood comprises a pair of wing members, each of which has a top portion and a side portion downwardly depending therefrom and downwardly and rearwardly depending rear portions coupled to the rear edges of the top and side portions. Track means are coupled on the outside surface of the top portions of each of the hood wing members and trolley means fixed to the underside of the intermediate frame slidably engage the track means to slidingly support the hood Wing members. The track means are substantially perpendicular to the direction of movement of the surface heater unit, thereby allowing each hood wing member to be moved laterally of the direction of movement.

A hood body member i slidably supported under the top portions of each of the pair of hood wing members by a trolley member fixed to the hood body member and riding in a track coupled to the underside of the above-described tracks. The hood body member comprises a center section and -a downwardly and r'ea'rwardly depending rear section coupled to a rear edge of the center section and the rear section of the hood body member is intermediate the surface to be heated and the rear portions of each of the hood wing members.

A plurality of burner port plates are fixedly coupled to a'forward edge of the center portion of the hood body member and a plurality of movable burner port plates are pivotally coupled to forward edges of the portion of each of the pair of hood wing members. The movable burner port plates coupled to the hood wing members may be swung upwardly to thereby clear the fixed burner port plates and nozzles associated therewith of the hood body portion when'the hood wing members are in a contracted or partially contracted position.

The pair of hood wing members and the hood body portion define an open bottom burner cavity and fuel and air are introduced therein from nozzles injecting through the burner port plates of both the hood "body portion and the hood wing members. The combustible mixture of fuel and air burns in the burner cavity and thermal energy is thereby generated and is transferred to the surface to be heated both by direct radiation from the products of combustion, and also byradiation from the interior surfaces of the hood wing members and the hood body portion.

The interior surface portions of the hood wing members'and the hood body member are provided with a heat resistant liner such as a refractory material or a heat resistant metal liner to aid in the transfer of thermal energy to the surface to be heated and also to prevent disintegration of the hood by excess temperature.

The hood wing members may be locked in a fixed position with respect to each other and with respect to the hood body portion and the entire hood may then be shifted laterally of the intermediate frame.

Means are also provided to pivotally swing upwardly the nozzles associated with the pivotally-mounted burner port plates on the pair of hood wing members as the hood is contracted and means are also provided to termihate the flow of fuel and air therethrough when the hood is in a contracted or partially contracted position and such burner port plates are not being utilized.

When the surface heater above-described is incorporated on a mobile vehicle for road use, applicants prefer to have the rear wheels thereof steerable to provide better maneuverability of the surface heater in operation.

In another embodiment of applicants invention the body portion of the hood is omitted and the movable hood wings are provided in an overlapping relationship to define the open bottom burner cavity. The pair of hood wings in this embodiment may also be individually movable laterally of the direction of movement of the surface heater to provide an increase and decrease in the burner cavity volume and also may be jointly shifted laterally to provide a change in the area to be heated with respect to the direction of'travel of the surface heater.

The above and other embodiments of applicants invention are more fully delineated in the following detailed description taken together with the accompanying drawings wherein similar reference characters refer to similar elements throughout in which:

FIGURE 1 is a side elevational view of one embodiment of applicants invention;

FIGURES 2, 3 and 4 are views, partially in section, illustrating the details of an expandable hood useful in the practice of applicants invention;

FIGURES 5 and 6 illustrate a support arrangement for an expandable hood useful in the practice of applicants invention;

FIGURES 7, 8 and 9 illustrate the arrangement for raising and lowering the expandable hood in applicants invention;

FIGURE 10 is a front perspective view of a preferred embodiment of applicants expandable hood illustrating the air supply and bu'rnerport arrangement-therefor;

FIGURE 11 illustrates the pivotally mounted burner port plates associated with applicants invention;

FIGURES 12 and 13 illustrate another embodiment 'of applicants invention;

FIGURE 14 illustrates the steerable rear wheels useful in the practice of applicants invention; and

FIGURE 15 illustrates a schematic representation of a hydraulic system'useful in the practice of applicants invention.

Referring now to FIGURE 1 there is shown aside view of one embodiment of applicants invention. As shown on FIGURE 1 there is a mobile surfaceheater, generally designated 10, and in this embodiment the mobile surface heater 10 comprises a tractor 12 pulling a semitrailer or fifth wheel trailer-type assembly generally designated 14. It will be appreciated that while the embodiment of applicants"invention shown in FIGURE 1 comprises the tractor 12 and trailer '14, many other arrangements of applicants invention may equally well be utilized. For example, instead of a separate tractor 12 and trailer 14, the mobile surface heater 10 may be-constructed as a unitary item of'mobile road equipment in which the trailer 14 actually comprises the chassis of such a mobile vehicle. Further, the embodiment shown in FIGURE 1 illustrates the utilization of applicants invention in a road heating type of surface heater adapted to be pulled along a road that is to be heated. Appli cants invention may also'be utilized instationary heating arrangements in which mobility of the heater is not required, such as firing or heating objects placed beneath the heater by conveyor or other means, and the like.

The trailer 14 comprises a stationary frame 16 coupled to the tractor 12 and is supported at the rear end by rear wheels 18. A movable intermediate frame 20 is supported from the stationary frame 16 by two hydraulically actuated, articulated bell crank members 22a and 22b, one of the hydraulically actuated articulated bell crank members 22a and 22b at each forward corner of intermediate frame 20.

It will be appreciated that articulated bell crank member 2212 does not show on FIGURE 1, as it is hidden by articulated bell crank member 22a. However, the articuated bell crank member 22b and its operation is similar to that described for articulated bell crank member 22a. A torque tube 23a couples articulated bell crank means 22a to a rear support linkage 27a at the rear corner of the intermediate frame 20. A similar torque tube 231) is coupled to a similar support linkage 27b at the opposite rear corner of intermediate frame 20. A pair of hydraulic actuators 122a and 1221) actuate respectively articulated bell crank means 22a and 22b and are pivotally coupled to the stationary frame 16. The details of the construction of the articulated bell crank means 22a and 22b and the support linkages 27a and 2717 are described in connection with applicants description of FIGURES 7,

8 and 9 herein.

Simultaneous actuation of hydraulic actuators 122a and 122b raise and lower the intermediate frame 20 in an even plane substantially parallel to the stationary frame 16. However independent actuation of either hydraulic actuator 122a or hydraulic actuator 1221; will raise or lower that side only of intermediate frame 20 to thereby tilt intermediate frame 20 about a longitudinal axis substantially parallel to the direction of traverse of the surface heater 10.

An expandable hood 26 is slidingly supported from the intermediate frame 20 and the expandable hood 26 defines an open-bottomed burner cavity 25, the open bottom of which faces the surface 24 to be heated. As explained below in greater detail, the expandable hood 26 may be expanded in a lateral direction perpendicular to the direction of travel of mobile surface heater 10 to increase and decrease the volume of the burner cavity 25 and also may be unitarily shifted in lateral directions to change the relative position of the expandable hood 26 and burner cavity 25 with respect to the intermediate frame 20 and the direction of travel of the mobile surface heater 10.

A combustible mixture of fuel from fuel tank 28 coupled to the stationary frame 16 and air from an air blower 30 coupled to the expandable hood 26 is introduced into the burner cavity 25 through nozzles and burned therein. The products of combustion generated thereby flow rearwardly through the burner cavity 25 and exhaust from the burner cavity at the rear end 25' thereof. A plurality of baffle plates, such as bafile plates 32 and 34, direct the exhausting products of combustion past rear wheels 18 so that the products of combustion may exhaust to atmosphere at the rear end 14 of the trailer 14, and provide additional heating at the surface 24 in the area 24.

In the embodiment shown on FIG. 1, other items of road working equipment such as a scarifier (not shown) may be coupled to the rear end 14 of the trailer 14 to be utilized in further road working operations.

FIGS. 2, 3, and 4 illustrate various details of applicants expandable hood 26. As shown thereon, the expandable hood 26 comprises three main sections: a left hood wing member 36, right hood wing member 38, and a hood body member 41 defining the open bottomed burner cavity 25. Each of the hood wing members 36 and 38 have top, or center, portions 40 and 42, respectively, downwardlydepending side wall portions 44 and 46, respectively, coupled to the top wall portions 40 and 42 and downwardly and rearwardly depending rear portions 48 and 50, respectively, coupled to the rear edge of the top portions 40 and 42 and the side wall portions 44 and 46.

The interior surfaces of each of the hood wings 36 and 38 are provided with a heat resistant liner such as a refractory material 52 adapted to withstand high temperatures. In the preferred embodiment of applicants invention, the refractory material 52 is utilized and comprises a cast refractory cast in place on the hood wings 36 and 38, and, as described below, on hood body member 41. It will be appreciated that a metal liner may be utilized, if desired, to provide the heat resisting and thermal radiating properties provided by the refractory material 52.

A pair of track means 54a and 54b are coupled to the outside of top portion 412 of right hood wing member 38 and extend transversely across the expandable hood 26 beyond the center thereof. Similarly, a pair of track means 56a and 56b are coupled to the outside of top portion 40 of left hood Wing member 36 and extend transversely across the center of expandable hood 26. In the embodiment shown, the track means 54a and 54b and 56a and 56b comprise I-beams as applicants have found that not only are I-beams available, but, in addition to providing the function of tracks, they also provide structural support to the hood wing members 36 and 38.

Each of the hood wing members 36 and 38 are slidingly supported from the intermediate frame 20 by a plurality of trolley means. Thus, hood wing member 36 is slidingly supported from the intermediate frame 20 by a pair of outer trolleys 60a engaging track means 56a and 60b engaging track means 5612. A pair of drive trolleys 61a and 612) are coupled to the intermediate frame 20 and engage the track means 56a and 56b respectively at approximately the center thereof. Similarly, hood wing member 38 is slidingly supported from intermediate frame 20 by a pair of outer trolleys 60a and 60b engaging, respectively, track means 54a and 54b. A pair of drive trolleys 61a and 61b are coupled to the intermediate frame 20 and engage the track means 54a and 54b, respectively, at approximately the center thereof.

The drive trolleys 61a and 61b provide the lateral shifting of the hood wing member 36 and the drive trolleys 61a and 6112' provide the lateral shifting of the hood wing member 38. FIGURE 5 illustrates the details of the drive trolley 61a and this is similar for the other drive trolleys 61a, 61b and 61b.

As shown on FIGURE 5, the drive trolley 61a comprises a pair of vertical support plates 62 coupled to the intermediate frame 2t). Applicants prefer that the vertical support plates 62 be bolted to the intermediate frame 20 to allow easy removal of trolley 61a for servicing and maintenance.

Four flanged wheels 64 are rotatably mounted on the vertical support plates 62 and engage the underside 66 of the top flange 68 of track means 54a.

A rack means 69 is coupled to the upper surface 71 of the upper flange 68 or track means 54a and the rack means 69 has a plurality of teeth engaging a drive wheel 73 coupled to a shaft 75 rotatably mounted on the vertical support plates 62. A roller 70 may also be includued to engage an untoothed portion of the track means 69 to insure that vertical loads will not be absorbed by the drive wheel 73. The roller 70 is coupled to the shaft 75 adjacent the drive wheel 7 3.

A sprocket is also coupled to the shaft 75 and a chain 94 engages the sprocket 90 and rotates the shaft 75 and the drive wheel '73. The chain 94 also engages a drive sprocket 96 coupled to a shaft 98 driven by rotary actuator 102 coupled to intermediate frame 20. The rotary actuator 102 may be electrically driven, hydraulically driven or mechanically driven from the main engine of the tractor 12 or by an auxiliary engine. As shown on applicants preferred embodiment, the rotary actuator 102 is hydraulically driven since applicants have found that hydraulic actuation of other actuating means associated with applicants surface heated 10 provides a unitary hydraulic system.

Another drive sprocket 96' coupled to the shaft 98 has another chain 94 in engagement therewith for driving the drive trolley 61b that engages the track means 54b at the forward end of hood wing member 38. Thus, actuation of the rotary actuator 102 drives the hood wing member 38 laterally of the intermediate frame 20 and the rotary actuator 102 is reversible so that the hood Wing member 38 may be driven both inwardly and outwardly.

A similar rotary actuator 102 is utilized to drive the drive trolleys 61a and 61b that engage, respectively, track means 56a and 56b of hood wing 36. Thus, independent or simultaneous actuation of the hood wing members 36 and 38 may be obtained either inwardly or outwardly from the intermediate frame 20 by either independent or simultaneous actuation of the rotary actuators 102 and 102'.

Since the expansion and contraction of the hood is often performed when the surface heater is not being utilized to heat a surface, that is, when the hood 26 is cold. Applicants have found that they may also expand and contract the expandable hood 16 by utilizing only one rotary actuator, such as rotary actuator 102 and drive trolleys 61a and 61b, for example, of hood wing member 38 and not .provide an independent drive means for the hood wing member 36. Expansion and contraction of the hood in such an embodiment is achieved by the following procedure.

Rotary acutato-r 192 is energized to drive the hood wing member 38 outwardly from the intermediate frame 20. The hood body member 41 is held in a fixed position relative to the intermediate frame 20, as for example, by hood body member coupling link members 72, while the expandable hood 26 is being expanded. When the hood wing member 38 has reached the desired extent of its lateral movement outwardly, a hood wing coupling link member 74 may be coupled to the top portions 40 and 42 of hood wing members 36 and 38. Rotary actuator 102 may then be reversed and hood wing member 38 is driven inwardly. Force is transmitted between hood wing member 38 and hood wing member 36 by link members 74 and this drives lhood wing member 36 outwardly to the extent desired of its lateral travel and in this position the hood wing member 38 is driven inwardly.

When hood wing member 36 is in its desired expanded condition, the link member 74 may be removed and hood wing member 38 may again be driven outwardly to expand the hood on both its left side and right side to any desired combination of an expanded condition.

However, such a procedure involves more time than would be used if the independent hydraulic rotary actuators 102 and 102' are provided to independently drive the hood wing members 38 and 36 and, in some embodiments, the savings of time may more than offset the additional cost of the rotary actuators 102' required for independent actuation of the two hood wing members 36 and 38.

The increase and decrease of the burner cavity 25 provided "by the expansion and contraction of the hood wing members 36 and 38 is useful in the'practice of appli'cants invention when, for example, it is necessary to either heat a wide trafiic lane or a narrow traffic lane in a single traverse by the surface heater 10.

The hood wing members 36 and 38 are also supported by outer trolley members 60a and 60b engaging the track means 56a and 56b, respectively, of hood Wing member 36 and 60a and 60b engaging the track means 54a and 54b, respectively, of hood wing member 36 and 60a and 60b engaging the track means 54a and 54b, respectively, of hood wing member 38. These trolleys are similar to the drive trolleys'61a and 61a except that only sliding support for the hood wing members 36 and 38 is provided thereby without any drive function. FIGURE 6 illustrates the details of outer trolley 60a which is similar for the other outer trolleys 60b, 60a and 60b. As shown thereon, a pair of vertically-disposed brackets 76 rotatably support a plurality of flanged wheel means 78 which engage the underside 66 of the upper flange 68 of track means 54a. The vertically-disposed brackets 76 are C OUPICid to the intermediate frame 20. Thus, each hood wing member 36 and 38 is supported by a total of four trolleys; two drive trolleys positioned approximately at the center of the expandable hood 26 and two outer trolleys in regions adjacent the outer edge thereof. This provides stabilized support for the hood wing members 36 and 38 and- .prevents tipping and rotation with respect to the intermediate frame 20 and hood body member 41. The outer trolleys are preferably bolted to the intermediate frame 20 so that they may also be removed for service and maintenance.

As shown on FIGURE 4, the hood body member 41 is slidingly supported by trolleys 80' coupled to I-beams 82 of the hood body member 41 and the trolleys 80 have flanged wheels 83 slidingly engaging track means 55 which are coupled to the underside of track means 54a and 54b. As shown, there are a total of four trolleys 80 supporting the hood body member 41 from the track means 55. The trolleys 80 are similar to the outer trolleys 60a except that trolleys 80 have a single pair of flanged wheels 83 instead of a double pair of flanged wheels 78. Applicants have found that such an arrangement provides satisfactory operation since the weight of only the hood body member 41, which is less than the combined weight of the body member 41 and the two wing members 36 and 38 carried by the outer trolleys 60a, 60a, 60b and 60b" and the drive trolleys 61a, 61b, 61a and 6l'b', is carried by the trolleys 80. For the configuration shown on FIGURE 4, applicants have provided the additional track means 55, coupled to the underside of track means 54a and 5412 because of the size limitations inherent in the embodiment shown. That is, if the trolleys 80 were to engage the track means 54a and 54b, interference might occur between them and the drive trolley 61a and 61b, as well as the outer trolleys 60a" and 60]), when the entire expandable lhood 26 is side shifted as described below in greater detail.

The hood body member 41 comprises a top portion 84, a downwardly and rearwardly-depending rear portion 86 coupled to a rear edge of the top portion 84 and the rear portion 86 is disposed beneath the rear portions 48 and 50 of hood wing members 36 and 38.

The entire expandable hood 26 may be side shifted laterally by utilization of the rotary actuators 102 and 102'. This may be accomplished by removing the links 72 coupling the hood body section 41 to the intermediate frame 20 and by coupling, for example, hood wing member 38 to the hood body member 41 by pin means 104 and by placing link members 74 between hood wing members 36 and 38. The hood wing members 36 and 38 may be in any desired expanded or contracted position with respect to the intermediate frame 20 and the hood body member 41. The link members 74 are provided with sufficient length to couple the hood wing members 36 and 38 in such relationship, and receptacles for pin means 104 in hood body member 41 are pro vided in the desired locations. In this configuration, the hood wing members 36 and 38 are rigidly coupled together and the hood body member 41 is rigidly coupled to the hood wing member 38. Therefore, either or both of the rotary actuators 102 and 102' may be utilized to drive the entire expandable hood 26 either left or-right laterally of the intermediate frame 20 in a unitary condition.

It will be appreciated, however, that if onlya single rotary actuator 102 is provided to drive the hood wing member 38 and there is no rotary actuator provided, such as rotary actuator 102', to drive the hood wing member 36, side shifting laterally of the intermediate frame 20 may also be provided by the above locking together of the three components ofthe expandable hood 26. That is, the rotary actuator 102 drives the hood 9 wing member 38 and this is rigidly coupled to both the hood body member 41 by the pin means 104 and to the hood wing member 36 by the link members 74.

Since lateral shifting of the expandable hood 26 is often performed during operation of the surface heater 10, that is, when it is heating a surface 25, applicants have found it advisable to couple the body member 41 and the hood wing members 36 and 38 together as above described after the expandable hood 26 has been expanded to its desired condition so that lateral shifting of the entire expendable hood 26 may be quickly and easily accomplished during traversal of any given road surface 24.

As described below in greater detail, the expansion of the expendable hood 26 in lateral directions is accomplished in discrete intervals, each interval corresponding to the width of a burner port plate provided at the forward end of both the hood body member 41 and the hood wing members 36 and 38. Therefore, infinite adjustment of the relative positions of the hood wing members 36 and 38 with respect to the hood body member 41 is generally not required and only fixed and known positions of the hood wing members 36 and 38 are utilized in the expansion of the expandable hood 26. If either hood wing 36 or 38 is moved laterally of the hood body member 41 in an increment different from one burner port spacing, operation of the hood 26 could be continued, but a gap would result in the forward end thereof.

Each hood wing member 36 and 38 may be expanded or contracted to any of its allowable positions independent of the relative position of the other hood wing member. Thus, for the embodiment shown wherein there are two burner port plates on each hood wing member, each hood wing member may be positioned in three discrete positions with respect to the hood body member 41. These three positions are: fully contracted as shown on FIG- URE 4, partially expanded where one burner port plate of the hood wing member is extended laterally beyond the edge of the hood body member, as shown for hood wing member 38 in FIG. 10, and fully opened or expanded where both burner port plates on the hood wing member are extended beyond the edge of the hood body member 41 as shown for hood wing member 36 in FIG. 10. It will be appreciated that if a greater number than the two burner port plates shown in this embodiment of applicants invention are provided on each hood wing member, there will be one more partially-opened position for each such burner port plate provided.

Each of the hood wing members 36 and 38 may be expanded to any of the three positions in the embodiment shown independently of the ultimate position of the other hood Wing member. When two rotary actuators, such as rotary actuators 102 and 102' are utilized, simultaneous actuation of hood wing members 36 and 38 may be accomplished to any of the three positions specified. When only one rotary such as rotary actuator 102 is provided, the procedure described above must be followed and in addition to providing a fully expanded condition as described above, can equally well be utilized to provide any combination of expanded or contracted hood wing relationships with respect to the hood body member 41.

Further, it will be appreciated that if the hood wing members 36 and 38 are sufficiently wide, then the additional track means 55 shown on this embodiment of applicants invention need not be provided, but rather the hood body member 41 may be slidingly supported directly from the same track means such as track means 54a and 54b.

The trolley means supporting the hood wing members 36 and 38 from the intermediate frame 20 could be coupled to the hood wing members themselves and slidingly engage tracks coupled to the underside of the intermediate frame 20, if desired. However, applicants prefer the arrangement shown since it does not require an extension of tracks beyond the edge of the intermediate frame 28 to support the hood wing members when they are in an expanded condition.

FIGURES 2, 3, and 4 also illustrate the preferred construction of the hood wing members 36 and 38 and the hood body member 41 of applicants invention herein. The construction of the hood wing members 36 and 38 are similar, the only substantial difference being the aforementioned addition of the track means 55 coupled to the track means 54a and 54b of hood wing member 38. As shown on FIGURES 2, 3, and 4, each of the hood wing members 36 and 38 comprise an outer skin such as outer skin 240 of the side portion 46 of hood Wing member 38. The outer skin 240 may be a sheet metal construction. A plurality of structural angles 242 are coupled to the outer skin 240 in a spaced relationship throughout the longitudinal length of the side wall portion 46. Each of the structural angles 242 are preferably tapered downwardly providing a smaller width at the bottom 238 of the side wall portion 46 than at the top 42 thereof.

A plurality of channels 244 are coupled to the angles 242 in a spaced relationship and extend substantially at right angles thereto to provide the main support members for the top portion 42 of the hood wing member 38. A channel 246 extends longitudinally throughout the length of the hood wing member 38 along the outer edge of the top portion 42 thereof and a channel 248 extends longitudinally throughout the length of the top portion 42 of hood wing member 38 along the inner side thereof and channels 246 and 248 are coupled to the top portion of the channels 244. Track means 55 are welded to the underside of track means 54a and 54b and this assembly of the two track means are coupled, in the position shown, to the channels 246 and 248. The channel 248 may be smaller than the channel 246 to allow an overlapping with the track means 55 and thus provide additional support therefor.

With the exception as noted above of the track means 55, the construction of hood wing member 36 is substantially identical to that above described for the hood wing member 38.

Refractory 52 provided on the interior surfaces of the hood wing member 38 is spaced from the angles 242 and the channels 244 a preselected distance as shown.

The refractory is supported on the angles 242 and the channels 244 by a plurality of T rods 250. The T-rods 250 are coupled to the channels 244 and the angles 242 and support the refractory 52a of hood wing member 38 in a spaced relationship therefrom to provide the gap 252 therebetween after the refractory 52a has been cast in place. A plurality of apertures 254 are provided in the outer skin 240. The apertures 254 allow free circulation of air between the refractory 52a and the outer skin 240 to prevent a build-up of pressure in the air gap 252, which might tend to fracture the refractory 52a. Further, the air gap 252 provides a passageway for drainage of any water, condensate or the like from the space between the refractory 52a and the other structure of hood wing member 38 to prevent such moisture or condensate from caus ing deleterious effects to the refractory 5211. A longitudinally extending cover plate 256 is provided between the channels 246 and 248 to protect the refractory 52a from weather and inadvertent damage throughout the longitudinal length of the hood wing member 38.

The hood body member 41 is constructed in a similar manner and has a plurality of horizontally-disposed channels 258 to which the I-beams 82, above described, are coupled. Cover plates 260 are coupled to the channels and to the I-beams 82 between each I-beam and the outer edges of hood body member 41 to protect the refractory 52b. The cover plate 268 may be sheet metal. Refractory 52b is supported by T rods 250 coupled to the channels 258 in a spaced relationship.

A plate 262 is coupled to the top of I-beams 82 to provide an air cavity 266 which, as described below, conducts air into the expandable hood 26 for secondary com- 1''1 bustion and cooling. The refractory 52b is spaced from the .channels 258 to provide an air gap 264 therebetween. Both the gaps 264 and 252 and the air cavity 266 also permit additional cooling of the components of the expandable hood 26 by allowing convective cooling of the refractory and supporting channels by conducting forced air therethrough.

The refractory 52b may be tapered, if desired, from the center outwardly toward the lateral edges thereof to allow drainage of any accumulated moisture or condensate. t

The T-rods 250 utilized to support the cast refractory material 52b on hood body member 411 and refractory 52 and 52a on hood wing members 36 and 38 are comparatively small in diameter and thin, rod-like angles could also be utilized in place of the T-rods 250 shown.

It will be appreciated that nonexpandable hoods may also be fabricated in accordance with the above-described structure.

As noted above, vertical positioning of the expandable hood 26 with respect to the surface 24 that is to be heated is accomplished by vertically moving the intermediate frame 20, to which the expandable hood 26 is slidingly coupled, with respect to the stationary frame 16 by the articulated bell crank means 22a and 22b and by the rear support linkages 27a and 27b. The details of this arrangement for the preferred embodiment of applicants invention are shown on FIGURES 7, 8, and 9.

It will be appreciated that articulated bell crank 22b is substantially identical to articulated bell crank 22a and that rear support linkage 27b is substantially identical to rear support linkage 27a. Articulated bell crank means 22a is comprised of a bell crank 116 rigidly coupled to the torque tube 23a. A channel 118 is pivotally coupled to an upper portion of the bell crank 116 by pivot pin means 120. The lowerend of the channel 118 is pivotally coupled to vertical support brackets 122, forming a part of the intermediate frame 20, by the pivot pinmeans 124. A shaft 126 of actuator 122:: is pivotally coupled to the bell crank 116 by pivot pin means 128 and for the position shown in FIGURES 7, 8, and 9, the shaft 126 is fully extended from the actuator 122a and the intermediate frame is in its vertically up condition moving the expandable hood 26 farthest from the surface 24.

This arrangement is preferred by applicants since the area of the piston 130 of hydraulic actuator 122a is greater on the side 130a thereof than on the side 13% thereof, and thus hydraulic pressure exerted against the side 130a of piston 130 is greater for raising the expandable hood 26 and intermediate frame 20 when they are being raised against the force of gravity.

The hydraulic actuator 122a is coupled to the intermediate frame 16 by the brackets 132. When it is desired to lower the intermediate frame 20 and expandable -hood 26, hydraulic pressure on the face 131m of the piston 130 is relieved and the force of gravity acting on the expandable hood 26 and its intermediate frame 20 causes 'them tobe lowered as the piston 130 moves rearwardly in the hydraulic actuator 12 2a.

The torque tube 23a is pivotally mounted in bearings 134 which are coupled to the intermediate frame16. The torque tube 23a actually comprises three sections: the first section 136 comprising a substantially solid rod that is coupled to the bell crank means 116 and to a tube member 138 which in turn is coupled to another rod-like memher 136' forming part of the rear support linkage 27a.

The rear support linkage 27a comprises a channel 184 .pivotally coupled to the intermediate frame 20 by pivot pin means 124' engaging vertical support bracket 122 of the intermediate frame 20. A link member 188 is pivotally coupled to the upper end of the channel 184 and is fixedly coupled to the rod-like section 136' of the torque tube 23a. .It will be appreciated that rear support linkage 27b is substantially identical in details of construc- 12 tion as that illustrated in FIGURE 9 for rear support linkage 27a.

When the torque tube 23a is rotated by the bell crank 116 through actuation of the hydraulic actuator 122a the link member 188 is also rotated since it is coupled to the torque tube 23a and the rear support 27a raises and lowers the rear end of the intermediate frame 20 and expandable hood 26 simultaneously with the raising and lowering of the forward end of the intermediate frame 20 and expandable hood 26 by the articulated bell crank means 22a. Simultaneous actuation of the hydraulic actuators 122a and 122k raises and lowers the intermediate frame 20 and expandable hood 26 in a substantially even vertical plane relative to the stationary frame 16. However, if the hydraulic actuators 122a and 1221) are individually operated, one side or the other of the intermediate frame 20 and expandable hood 26 will be raised or lowered with respect to the other side thereof, thereby pivoting the intermediate frame 20 and expandable hood 26 about a longitudinal axis substantially parallel to the direction of traverse of the surface heater 10. This is often useful when the hood 26 is heating a crowned surface as is found on many streets and highways.

It will be appreciated, however, that, if desired, applicants invention may also be embodied in an arrangement in which more than two articulated bell crank means may be utilized to raise and lowerthe intermediate frame 20 and expandable hood 26. For example, four independently actuatable bell crank means with four separate hydraulic cylinders might be provided, one of such bell crank means at each corner of the intermediate frame 20. Such an arrangement would allow not only tilting about a longitudinal axis parallel to the direction of traverse of the surface heater 10, but also pivoting about a transverse axis substantially perpendicular to the direction of traverse of the surface heater 10.

Many other arrangements could also be utilized to raise and lower the intermediate frame 20 and expandable hood 26. For example, jack screws or chain hoists or-any other means could be utilized as equivalents of the articulated bell crank means 22a and 22b and rear support linkages 27a and 27b illustrated by applicants in the preferred embodiment of their invention.

As can be seen from FIGURE 8, the bell crank 116 of articulated bell crank means 221: has a portion 116' closely adjacent the channel 118. This close proximity of the channel 118 and the bell crank 116 prevents undesirable rotary oscillations about pivot pin 120 during travel of the surface heater 10.

In order to minimize the :weight of applicants surface heater 10, applicants have found itdesirable that both Thus, cover plates or other members may be omitted 'from both; the intermediate frame 20 and the stationary frame 16 included on the surface'heater 10. Further, by eliminatso that additional weight vis not unnecessarily ing any coverplates thereon, access to the upper surfaces Of the hood wings 36 and 3 8 and hood body member 41 may also be easily achieved when necessary for maintenance and repair, or for coupling and decoupling during expansion and contraction ofthe expandablehood 26 and lateral shifting thereof.

Thermal energy is generated in the expandable hood 26 by the injection of a combustible mixture of fuel and air through burner portplates coupled to the forward end of the hood wing members36 and 38 and the hood body member 41. In order/to allow the expansion and contraction of the expandable hood 26 by lateral movement of the hood vwing members 36 and 38, applicants have provided pivotally mounted burner port plates coupled to the forward end of each of thevhood wing members 36 and 38. *Fixed'burner port plates are coupled to the forward end of the hood body member 41.

This is illustrated in the perspective view of FIGURE which shows the hood wing member 38 in a half expanded position and the hood wing member 36 in a fully expanded position. Hood wing member 38 has burner port plates 140 and 142 pivotally coupled along a forward edge 146 thereof. The burner port plate 140 is in the down position for the-configuration shown on FIGURE 10, since it is beyond edge 166 of the hood body member 41. The burner port plate 142 of hood wing member 38, however, is pivotally swung upwardly to clear the fixed burner port plate 144 of the hood body member 41. The burner port plate 142 may be supported in its up position by, for example, a chain means 146. Similar chain means (not shown on FIGURE 10) may be provided to support the other burner port plate 140 of hood wing member 38 and the burner port plates 148 and 150 pivotally mounted to hood wing member 36.

In general, applicants have found that the weight of the pivotally mounted burner port plates is suflicient to maintain them in the down position as illustrated by burner port plates 140, 148 and 150 without additional locking or clamping means. However, it will be appreciated that clamp means may easily be provided on the pivotally mounted burner port plates to maintain them in the down position.

Both burner port plates 148 and 158 of hood wing member 36 are shown in a down position as hood wing member 36 has been moved laterally to its fully extended position beyond the hood body member 41.

Each of the hood wing members 36 and 38 may be moved laterally in intervals of one burner port plate width. This corresponds to the width of one burner port plate.

While only two pivotally mounted burner port plates are shown for each of the hood wing members 36 and 38 and six burner ports in burner port plate 144 at hood body member 41, it will be appreciated that any number of burner port plates may be provided thereon to allow expansion of the expandable hood 26 to any desired degree for a given application.

In the preferred embodiment of applicants invention, the fixed burner port plate 144 attached to hood body member 41 and the pivotally mounted burner port plates 140 and 142 of hood wing member 38 and pivotally mounted burner port plates 148 and 150 of hood wing member 36 are substantially coplanar when the pivotally mounted burner port plates are in the down position. This provides a more even heat distribution throughout the width of the expandable hood 26.

The interior of both the pivotally mounted burner port plates on each hood wing member and the fixed burner port plate on the hood body member are provided with a heat resistant liner, such as a refractory material (not shown), on the interior surfaces thereof in a manner similar to that described for the attachment of the refractory to other portions of the expandable hood 26.

Each of the pivotally mounted burner port plates 140, 142, 148 and 150 has an aperture 168 therein and the fixed burner port plate 144 has a total of six apertures 114 therein. These apertures provide access to the burner cavity 25 of the expandable hood 26 for the injection of a combustible mixture of fuel and air thereon. However, as shown on FIGURES 10 and 11, applicants provide that the portions of the manifold 156 supplying air to the hood wing members 36 and 38, such as sections 178 and 180, be coupled to the center portion 176 of the manifold 156 supplying air to the nozzles 152 of the hood body member 41 by flexible hose sections 170 and 172, respectively, which will bend and allow the hood wing members 36 and 38 to be moved in and out without interrupting the air supply thereto.

Forced air from blower 30 is supplied to the manifold 156 by feed line 174. The blower 30 is mounted on the I-beams 82 of the hood body member 41 and thus move vertically up and down with the expandable hood 14 26 as it is raised and lowered from the stationary frame 16.

In the preferred embodiment of applicants invention, the top portion 84 of hood body member 41 is cooled to prevent overheating thereof since in the contracted position it does not have free radiation along the outer portions thereof to the cooler atmosphere, but, rather, faces the heated refractories 52 and 52a of the hood wing members 36 and 38 as shown on FIGURE 4. In addition to cooling the upper surface 84, applicants have also found it desirable to provide secondary combustion air in the burner cavity 25 throughout the length thereof so that any unburned fuel injected into burner cavity 25 through the nozzles 152 and 152 may be burned to provide a cleaner exhaust and more complete and efficient utilization of the fuel. Further, applicants have found it desirable to prevent the back flow of combustion products up the spaces 192 and 194 between the hood wing members 36 and 38 and the hood body member 41, respectively, as shown on FIGURE 4.

These advantages are achieved, according to the preferred embodiment of applicants invention, by providing a fan and radiator arrangement 280 coupled to a shaft 282 which is rotated by, for example, a hydraulic rotary actuator 284 that also drives the blower 30. Air is conducted from the fan and radiator arrangement 288 by duct means 286 into the air cavity 266 formed by the upper plate 262 coupled to each of the I-beams 82. Air flows through the duct 286 into the air cavity 266 and then outwardly toward the edges of hood body member 41 in the spaces between the channels 258 and in the gap 264 in a direction shown by the arrows A and B on FIGURE 4. The air is prevented from flowing upwardly by the cover plates 260. This forced flow of air through the spaces between the channels 258 in hood body member 41 comes down through the passageways 192 and 194 and thereby not only cools the upper surface 196 of the refractory 52b and the supporting channels 258, and supplies additional air for burning the fuel in the burner cavity 25, but also prevents the back flow of combustion products upwardly in the spaces 192 and 194.

A combustible mixture of fuel and air is injected through the apertures 168 in the pivotally mounted burner port plates by nozzles 152. The nozzles 152 and 152' are of conventional design, such as North American Mfg. Co., of Cleveland, Ohio, Model #2004.

This type of nozzle mixes fuel as fed to each nozzle 152 and 152 through flexible fuel lines 154 with forced air fed through manifold 156 into the pivotally mounted tube means 158 for each pivotally mounted burner port plate 140, 142, 148 and 150. Similarly, air is supplied to the fixed tube means 168 for the nozzles 152 of the fixed burner port plate 144 on hood body member 41. The nozzles 152 and 152 are supported by the tube members 158 and 160', respectively.

Tube members 158 supplying air to the nozzles 152 of the pivotally mounted burner port plates 148, 142, 148 and 150 are pivotally mounted on the manifold 156 and applicants provide means for automatically terminating the flow of air therethrough when the burner port plates are lifted to their up position. The pivotally mounted tube means 158 swing upwardly on manifold 156 to the position, for example, of tube means 158. As shown on FIGURE 11 which illustrates in solid lines the tube means 158 in a down position, the manifold 156 is provided with an aperture 198 registrably alignable to the opening in the tube 158 to allow the flow of air therethrough into the nozzle 152, where it is mixed with fuel entering the nozzle 152 from fuel line 154.

When the tube means 158 is swung in the direction of arrow 162 to the up position, shown in dotted lines on FIGURE 11, aperture 161 on the manifold 156 no longer is aligned with the opening in the tube means 158' and the flow of air therethrough is terminated.

Valve means 164 are provided on each of the fuellines 154 to terminate the flow of fuel when each of the nozzles 152 is not being utilized.

If desired, the manifold 156 may be made telescoping to allow the entire manifold to move inwardly and outwardly with the movement of the hood wing members 36 and 38.

When the surface heater 10 is being utilized to heat a particular surface, rear wheels 18 which generally are steel are utilized so that'they may pass over the heated surface without damage to them. However, for road transportation operation, regular pneumatic tires and wheels are generally provided and these may be bolted to the rear wheels 18 as shown on FIGURE 1. Wheels 182 with road tires may be pivotally coupled to the stationary frame 16 by arm means 186 to allow swinging the road wheels 182 into the down position when it is desired to transport the surface heater 10 over the road when the expandable hood 26 is not being operated. The pivotally mounted road wheels 182 may be secured in the up position as shown on FIGURE 1, by, for example, chain means 187 to restrain them in the up position.

If the length of the surface heater 10 is comparatively great, applicants have found it advantageous to provide independent steering for the rear wheels 18. This arrangement is illustrated on FIGURE 14. As shown, each of the rear wheels 18 is rotatably mounted in a yoke 300 that is pivotally coupled to the stationary frame 16. Links 302 are coupled to the yoke 300 and are connected by a tie rod 308 having a turnbuckle 298 for adjusting the parallelism of the wheels 18. A hydraulic actuator 304 is pivotally coupled to the stationary frame 16 and shaft 306 thereof is pivotally coupled to one of the link members 302a. Extension and retraction of the shaft 306 rotates both rear wheels 18 in directions indicated by the arrow C. In the preferred embodiment of applicants invention, control of the hydraulic actuator 304 is effected by the driver of the tractor 12; however, it will be appreciated that independent steering of the rear wheels 18 could also be accomplished from the rear of the surface heater 10 if desired. A reversible electric or hydraulic motor coupled to the rod 308 by a rack and gear assembly could also be utilized.

Applicants have found that utilization of hydraulic actuators for the various functions above-described allows shifting of either the individual hood wings 36 and 38 or of the expandable hood 26 by the rotary hydraulic actuators 102 and 102. The rotary actuators 102 and 102 are preferably of the type that may be driven either clock wise or counterclockwise so that both expansion and contraction of the expandable hood 26, as well as lateral shifting to the left and to the right of the entire expandable hood 26, may be accomplished from the same rotary actuators.

The hydraulic motor 284 drives a fan 288 in the fan and radiator arrangement 280. The radiator portion of the fan and radiator arrangement 280 is designated 290 on FIGURE 15 and receives the hydraulic fluid from the return lines of the above-described linear and rotary actuators. Hydraulic fluid passes through the radiator 290 where it is cooled by the forced draft generated from the rotation of the fan 288. The forced draft thus generated is, as described above, utilized for the second combustion in the burner cavity 25 and cooling and sealing the upper surface of thehood body. member 41.

The hydraulic oil leaves the radiator 290 and is collected in a sump 310 communicating with a hydraulic pump 312. The hydraulic pump 312 is driven by a motor 314 which may be electrically driven or gear driven from the engine in tractor 12. It will be appreciated that the motor or rotary actuator 284 rotating the fan 288 may similarly be electrically or gear-driven, as well as the hydraulically-driven actuator illustrated.

Hydraulic oil flow in the various lines is in the direction indicated by the arrows shown on FIGURE 15. Hydraulic oil flows from the pump to the valves controlling the individual hydraulic actuators. Similarly, hydraulic oil from the pump 312 flows through a valve 2% controlling the hydraulically operated motor 284. The valves 316 control the fiow of oil to the linear actuators 122a and 122b, utilized for raising and lowering the intermediate frame 20 and expandable hood 26. These valves may be of the conventional 3-way type hydraulic valve, and for extension of the shafts thereof to raise the intermediate frame 20, oil flows from the inlet of the-valve into the actuators 122a and 122b. Retraction of the shafts thereof allows the intermediate frame 20 and expandable hood 26 to lower and sufficient pressure is generated in the hydraulic linear actuators 1212a and 122b by gravity forces acting on the hood 26 and intermediate frame 20 to return the oil through the valve and into the sump 310. The valves 3 16 controlling the operation of the actuators 122a and 1221) may be operated either individually or jointly to provide either uniform raising and lowering of the expandable hood 26 or tilting thereof about a longitudinal axis as described above.

The valve 318 controls the flow of hydraulic fluid into the linear actuator 304 utilized to steer the rear wheels 18. This valve is of the conventional 4-way variety and controls the flow so that the shaft of the linear actuator 304 may be extended or contracted to steer the wheels left and rights as desired.

The valves 320 control the flow of hydraulic oil through the rotaryhydraulic actuators 102 and 102' for expanding the hood 26 by lateral movement of either or both the hoodwings 36 and 38 or lateral shifting of the entire expandable hood 26. The valve 320 controls the hydraulicoil so that forward or reverse rotation of therotary actuators .102 and 102 may be obtained and may be operated either jointly or individually depending upon the desired shifting.

Applicants have also found that an expandable hood, according to applicants invention herein, may valso be fabricated by a pair of overlapping or abutting hood wing members Without utilizing a central body member as in the embodiment described above. One such arrangement is illustrated in FIGURES 12 and 13. As shown thereon,

an expandable hood 200 is comprised, generally, of a first hood wing member 202 and a second hood wing member 204 defining a burner cavity 205. As shown, the hood wing member 202 and hood wing member 204 overlap when in a partially closed or totally closed position. Each of the hood wing members 202 and 204 are slidingly supported from an intermediate .frame 206, which may be similar to the intermediate frame 20 of the embodiment of applicants invention described above. The intermediate frame 206 may be supported from a stationary frame (not shown on FIGURE 12 in a manner similar to that described above.

-Drive trolley means 208 similar to drive trolleys 61, 61a,.61b, and 61b, are coupled to the intermediate frame 206 and have wheel members riding in track means 21.0 of hood wing member 202. A rotary actuator 212 drives the trolley means 208 through a chain 214 and a sprocket coupled to the drive trolley means 208 in a manner similar to that described above. Similarly, hood wing member-204 is slidingly supported from the intermediate frame 206 by drive trolley means 216 coupled to intermediate frame 206 and having wheel means engaging track means .218 coupled to hood wing .member 204. A rotary 17 actuator 212 which may be similar to rotary actuator 212 drives drive trolley means 216 by a chain means 220 to move the hood wing member 204 laterally of the intermediate frame 206 to expand and contract the expandable hood 200.

Intermediate supports 222 and 224 are coupled to the intermediate frame 206 and have Wheel means engaging both track means 210 of hood wing member 202 and track means 218 of hood wing member 204. The intermediate supports 222 and 224 maintain the two hood wings 202 and 204 in a fixed vertical spatial relationship and also absorb any overhung moment generated thereby.

The forward portion of each of the hood wing members 202 and 204 are closed by a plurality of burner port plates. Thus, a plurality of fixed burner port plates 226 are coupled to hood wing member 204 and a plurality of movable burner port plates 228 are pivotally coupled to hood wing member 202. The burner port plates 228 coupled to the hood wing member 202 are pivotally mounted in a manner similar to that described above and may be pivoted upwardly to clear the fixed burner port plates 226 when the hood Wing member 202 is in a contracted position with respect to the hood wing member 204. This position is illustrated, for example, by the pivotally mounted burner port plates 228a and 22% shown in their pivoted up position to clear the fixed burner port plates 226 of the hood wing member 204. The air supply and fuel supply to the expandable hood 200 is similar to that described above.

A pin means 230 sliding through a clevis 232, coupled to hood wing 202 and engaging the hood wing 204 in discreet intervals of one burner port plate width, is utilized to lock the two hood wing members 204 and 202 together to allow unitary lateral movement of them. Thus, side shifting of the entire expanded or partially expanded hood 200 may be accomplished through the utilization of either or both actuators 220 and 212, to move the entire expandable hood 200, comprised of both the hood wing members 202 and 204 locked in a preselected position, laterally of the intermediate frame 206. Similarly, link members 234 and 236 may be utilized to temporarily couple the hood wing members 202 or 204 to the intermediate frame 206 when it is desired to expand only one side of the expandable hood 206.

It will be appreciated that instead of an overlapping hood wing arrangement as illustrated on FIGURES 12 and 13, applicants invention also may be practiced by abutting hood wing member in which the burner port plates are hinged along a vertical line to allow them to swing forwardly to clear the fixed burner port plates mounted on the other hood wing member. In such an embodiment, sections of the entire top structure including track means for supporting the hood wing members would be made either removable or pivotally mounted to allow clearance when the hood wing members are in a contracted position.

As described above in the preferred embodiments of applicants invention, applicants prefer to have the trolley means by which the expandable hood is supported from an intermediate frame coupled to the laterally stationary intermediate frame as opposed to the laterally movable intermediate frame. This eliminates necessity for having track means coupled to the intermediate frame extending in a fixed position beyond the nominal edge of the intermediate frame. Thereby, the overall width of the surface heater may be maintained within applicable limits.

In addition, applicants prefer to utilize in the practice of their invention the articulated bell crank means illustrated for the support of intermediate frame and for raising and lowering thereof. The articulated bell crank means with the arm members coupled to the bell crank and to the intermediate frame provide greater rigidity than has previously been achieved by other suspension means such as chains or cables which are flexible and cannot take compressive forces. Applicants connecting arms, on the other hand, can absorb both tension forces as well as compressive forces.

From the above, it can be seen that applicants have provided an improved surface heater arrangement. Applicants surface heater arrangement provides not only an expandable hood, so that varying widths of a surface may be heated in a single traverse of the road heater, but also one in which the entire expandable hood may be side shifted laterally of the surface heater to provide a change in the particular path of heating with respect to the direction of traverse of the surface heater.

It will be appreciated that those skilled in the art will 7 find many adaptations and variations of applicants invention herein. For example, if vertical adjustment of applicants expandable hood is not required, the expandable hood may be slidingly coupled to a stationary frame to provide only lateral side shifting and expansion and contraction of the hood, without the provision of vertical adjustment from the surface to be heated. Further, applicants expandable hood may also be provided in a non-mobile arrangement such as, for example, a paint dryer for large painted areas. In such an arrangement, the painted areas may be passed progressively under the expandable hood by means of a continuous belt or similar such device and applicants expandable hood would remain stationary.

Therefore, the following claims are intended to cover all such adaptations and variations of applicants invention falling within the true scope and spirit thereof.

We claim:

1. A surface heater comprising in combination: a frame member; supporting wheels coupled to said member; an intermediate frame movably coupled to said frame member for relative vertical movement with respect to said frame member; motion producing means coupled to said frame member and said intermediate frame for vertically moving said intermediate frame with respect to said frame member; a pair of hood wing members, slidingly supported from said intermediate frame member and each of said hood wing members comprising a top portion, a downwardly-depending side wall portion coupled to an outer edge of said top portion, and a downwardly-depending back portion coupled to a rear edge of said top portion and a rear edge of said side Wall portion, and at least one of said pair of hood wing members having a plurality of movable burner plates pivotally coupled to a forward edge of said top portion, and a heat resistant material coupled to preselected interior surface portions of each of said hood Wing members, said pair of hood wing members defining a volume comprising at least part of a burner cavity; means for slidingly moving said pair of hood wing members laterally of said intermediate frame to selectively increase and decrease the volume defined by said pair of hood wing members and to shift said pair of hood wing members laterally of said intermediate frame; and means for generating thermal energy in said volume defined by said pair of hood wing members.

2. A surface heater comprising in combination: a frame member; supporting wheels coupled to said frame member; an intermediate frame movably coupled to said frame member; motion producing means coupled to said frame member and said intermediate frame for vertically moving said intermediate frame with respect to' said frame member; a pair of hood wing members, slidingly supported on said intermediate frame member and each of said hood wing members comprising a top portion, a downwardly-depending side wall portion coupled to an outer edge of said top portion, and a downwardly-depending back portion coupled to a rear edge of said top portion and to said side wall portion, and at least one of said hood wing members having a plurality of movable burner plates pivotally coupled to a forward edge of said top portion, and a heat resistant material coupled to preselected interior surface portions of each of said hood wing members, said pair of hood wing members defining a volume comprising at least a portion of an open bottomed burner cavity; track means coupled to exterior surface portions of the top portion of each of said pair of hood wing members; support means coupled to said intermediate frame and having wheel members engaging said track means on said pair of hood wing members to slidingly support said pair of hood wing members therefrom; means for moving each of said pair of hood wing members on said support means laterally of said intermediate frame to selectively increase and decrease the volume defined thereby; means for unitarily moving said pair of hood wing members laterally of said intermediate frame; and means for generating thermal energy in the interior of said pair of hood Wing members and said hood body member.

3. An expandable hood for a surface heater comprising, in combination: a body member having a center portion, a downwardly and rearwardly depending rear portion coupled to a rear edge of said center portion, a plurality of downwardly-depending burner port plates coupled to a forward edge of said center portion, and a heat resistant material coupled to preselected interior surface portions of said body member; a pair of spaced wing members supported in spaced-apart relationship from exterior surface portions of said body member and each of said wing members comprising a top portion spaced from exterior surfaces of said center portion of said body member and substantially coextensive in length therewith and less than one-half the width thereof; a downwardly-depending side portion coupled to an external edge of said top portion and substantially coextensive in length therewith, a downwardly and rearwardly depending rear portion coupled to a rear edge of said top portion and to said side portion and spaced apart from exterior portions of said rear portion of said body member, and a plurality of movable burner port plates pivotally coupled to a forward edge of said top portion, and each of said movable burner port plates adapted to be selectively pivoted upwardly to clear said plurality of burner port plates coupled to said top portion of said body member, and a heat resistant material coupled to preselected interior surface portions of each of said wing members, said body member and said pair of wing members defining an open bottom burner cavity; means for suspending said body member from at least one of said wing members; means for moving each of said wing members laterally of said body member to change the volume of said burner cavity; and means mounted adjacent said plurality of burner plates and said plurality of movable burner port plates for injecting therethrough a combustible mixture of fuel and air into said burner cavity to generate thermal energy therein.

4. An expandable hood for a surface heater comprising, in combination: a body member having -a center portion, a downwardly-depending rear portion coupled to a rear edge of said center portion, a plurality of downwardly-depending burner port plates coupled to a forward edge of said center portion and a refractory material coupled in spaced relationship to preselected interior surface portions of said body member; a pair of spaced wing members supported in spaced-apart relationship from exterior surface portions of said body member and each of said wing members comprising a top portion spaced from exterior surfaces of said center portion of said body memher and substantially coextensive in length therewith and less than one-half the Width thereof; a downwardly-depending side portion coupled to an external edge of said top portion and substantially coextensive in length therewith, a downwardly-depending rear portion coupled to said top portion and to said side' portion and spaced apart from exterior portions of said rear portion of said body member, and a plurality of movable burner port plates pivotally coupled to a forward edge of said top portion and each of said movable burner port plates adapted to be selectively pivoted upwardly to clear said plurality of burner port plates coupled to said top portion of said body member and a refractory material coupled in spaced relationship to preselected interior surface portions of each of said wing members, said body member and said pair of wing members defining an open bottom burner cavity; laterally positioned track means coupled to exterior surface portions of said top portion of at least one of said wing members and having interior track portions spaced from said center section of said body member; support means coupled to the exterior surface of said center portion of said body member intermediate said wing members and having wheel members engaging said interior track portions of said track means for slidingly supporting said body member from said pair of wing members; motion producing means for slidingly moving each of said pair of wing members laterally of said body member to increase and decrease the VOllHIlfi of said burner cavity; and means mounted adjacent said plurality of burner port plates and said plurality of movable burner port plates for injecting therethrough :a combustible mixture of fuel and air into said burner cavity to generate thermal energy therein.

5. A surface heater comprising, in combination: a mobile vehicle having a chassis; an intermediate frame movably coupled to said chassis for vertical and pivotal movement with respect to said chassis; means coupled to said chassis and said intermediate frame for vertically moving said intermediate frame with respect to said chassis and for pivoting said intermediate frame about a horizontal axis with respect to said chassis; a pair of hood wing members each of said hood Wing members comprising a substantially vertically diposed side wall portion and substantially horizontally disposed top portion, and a back poriton coupled to said top portion and said side wall portion, and at least one of said pair of hood wing members having a plurality of movable burner port plates pivotally coupled to a forward edge of said top portion, and a refractory material coupled in spaced relationship to preselected interior surface portions of each of said hood wing members; track means coupled to external surfaces of said top portion of each of said hood wing members and said track means intermediate said intermediate frame and said top port-ions; suspension means coupled to said intermediate frame and having wheel members riding in said track means for slidingly supporting said hood wing members on said intermediate frame; means for moving each of said pair of hood wing members laterally of said intermediate frame on said suspension means; lock means for locking each of said pair of hood wing members 1n a preselected relationship; means for unitanily moving said pair of hood wing members laterally of said intermediate frame; means for burning a preselected amount of fuel and air in .said hood Wing members between said slde Wall portions to thereby heat a predetermined surface disposed beneath said hood wing members.

6. An improved hood for a surface heater comprising, in combination: a body member having a center portion, a downwardly-depending rear portion coupled to a rear edge of said center portion, a plurality of downwardlydepending burner port plates coupled to a forward edge of said center portion and a refractory material coupled in spaced relationship to preselected interior surface portrons of said body member; a pair of spaced wing members supported in spaced-apart relationship from exterior surface portions of said body member and each of said wing members comprising a top portion spaced from exterior surfaces of said center portion of said body member and substantially coextensive in length therewith and less than one-half the width thereof; a downwardly-depending side portion coupled to an external edge of said top portion and substantially coextensive in length there wlth, a downwardly-depending rear portion coupled to a rear edge of said top portion and to said side portion and spaced apart from exterior portions of said rear portion of said body member, and a plurality of movable burner port plates pivotally coupled to a forward edge of said top portion and each of said movable burner port plates adapt-ed to be selectively pivoted upwardly to clear said plurality of burner port plates coupled to said center portion of said body member, and a refractory material coupled in spaced relationship to preselected interior surface portions of each of said Wing members, said body member and said pair of wing members defining an open bottom burner cavity; means for moving each of said wing members laterally of said body member to change the volume of said burner cavity; means mounted adjacent said plurality of burner plates and said plurality of movable burner port plates for injecting therethrough a combustible mixture of fuel and air into said burner cavity to generate thermal energy therein; and means for selectively terminating the injection of fuel and air through said plurality of movable burner port plates.

7. An improved hood for a surface heater comprising, in combination: a body member having a center portion, 1a downwardly and rearwardly depending rear portion coupled to a rear edge of said center portion, a plurality of downwadly-depending burner port plates coupled to a for ward edge of said center portion and a refractory material coupled to preselected interior surface portions of said body member; a pair of spaced wing members supported in spaced-apart relationship from exterior surface portions of said body member and each of said wing members comprising a top portion spaced from exterior surfaces of said center portion of said body member and substantially coextensive in length therewith and less than one-half the width thereof; a downwardly-depending side portion coupled to an external edge of said top portion and substantially coextensive in length therewith, a downwardly and rearwardly depending rear portion coupled to said top portion and to said side portion and spaced apart from exterior portions of said rear portion of said body member, and a plurality of movable burner port plates pivotally coupled to a forward edge of said top portion and each of said movable burner port plates adapted to be selectively pivoted upwardly to clear said plurality of burner port plates coupled to said center portion of said body member, and a refractory material coupled to preselected interior surface portions of each of said wing members, said body member and said pair of wing members defining an open bottom burner cavity; laterally positioned track means coupled to exterior surface portions of said top portion of at least one of said wing members and having interior track portions spaced from said center section of said body member; support means coupled to the exterior surface of said top portion of said body members intermediate said wing members and having wheel members engaging said interior track portions of said track means for slidingly supporting said body member from said at least one of said pair of wing members; means for slidingly moving each of said pair of Wing members laterally of said body member to increase and decrease the volume of said burner cavity; means mounted adjacent said plurality of burner plates and said plurality of movable burner port plates for injecting therethrough a combustible mixture of fuel and air into said burner cavity to generate thermal energy therein; and means for selectively terminating the injection of fuel and air through said plurality of movable burner port plates.

8. An expandable hood for a surface heater comprising, in combination: a pair of overlapping wing members each of said pair of overlapping wing members comprising a substantially horizontally-disposed center portion, a downwardly-depending side wall portion coupled to an external edge of said center portion, a downwardly and rearwardly-depending rear portion coupled to a rear edge of said center portion and to said side portion, a plurality of movable burner port plates pivotally coupled to a forward edge of said center portion of at least one of said wing members, and a refractory material coupled in spaced relationship to preselected interior surface portions of each of said overlapping wing members, a first of said pair of wing members vertically spaced a preselected distance from the other of said pair of wing members and said pair of wing members defining an open bottom burner cavity; and means for moving each of said wing members laterally of the other of said wing members to change the volume of said burner cavity.

9. An improved hood for a surface heater comprising, in combination: a body member having a center portion, a downwardly and rearwardly-depending rear portion coupled to a rear edge of said center portion, a plurality of downwardly-depending burner port plates coupled to a forward edge of said center portion and a heat resistant coating coupled in spaced relationship to preselected interior surface portions of said body member; a pair of spaced wing members supported in spacedapart relationship from exterior surface portions of said ,body member and each of said wing members comprising a top portion spaced from exterior surfaces of said center portion of said body member and substantially coextensive in length therewith and less than one-half the width thereof; a downwardly-depending side portion coupled to an external edge of said top portion and substantially coextensive in length therewith and spaced from exterior edge portions of said center port-ion of said body member, and defining a gap therebetween a downwardly and rearwardly-depending rear portion coupled to a rear edge of said top portion and to said side portion and spaced apart from exterior portions of said rear portion of said body member, and a plurality of movable burner port plates pivotally coupled to a forward edge of said top portion and each of said movable burner port plates adapted to be selectively pivoted upwardly to clear said plurality of burner port plates coupled to said center portion of said body member and a heat resistant material coupled in spaced relationship to preselected interior surface portions of each of said wing members, said body member and said pair of wing members defining an open bottom burner cavity; means for slidingly supporting said body member from at least one of said hood wing members; means for moving each of said wing members laterally of said body member to change the volume of said burner cavity; and means for conducting air along said center portion of said body member and into said burner cavity through said gap between exterior edge portions of said center portion and said side portions of said wing members substantially throughout the length thereof for convectively cooling said center portion and preventing upflow of gases from said burner cavity in said preselected distance.

10. An improved hood for a surface heater comprising, in combination: a body member having a center portion, a downwardly-depending rear portion coupled to a rear edge of said center portion, a plurality of downwardlydepending burner port plates coupled to a forward edge of said center portion and a refractory material coupled in spaced relationship to preselected interior surface portions of said body member; a pair of spaced wing members supported in spaced-apart relationship from exterior surface portions of said body member and each of said wing members comprising a top portion spaced from exterior surfaces of said center portion of said body member and substantially coextensive in length therewith and less than one-half the width thereof; a downwardly depending side portion coupled to an external edge of said top portion and substantially coextensive in length therewith, a downwardly-depending rear portion coupled to a rear edge of said top portion and to said side portion and spaced apart from exterior portions of said rear portion of said body member, and a plurality of movable burner port plates pivotally coupled to a forward edge of said top portion and each of said movable burner port plates adapted to be selectively pivoted upwardly to clear said plurality of burner port plates coupled to said center portion of said body member and a refractory material coupled in spaced relationship to preselected interior surface portions of each of said wing members, and said body member and said pair of wing members defining an open bottom burner cavity.

11. An expandable hood for a surface heater comprising, in combination: a pair of overlapping wing members each of said pair of overlapping wing members comprising a substantially horizontally-disposed center portion, a downwardly-depending side wall portion coupled to an external edge of said center portion, a downwardly and rearwardly-depending rear portion coupled to a rear edge of said center portion and to said side portion, a plurality of movable burner port plates pivotally coupled to a forward edge of at least one said center portions and a refractory material coupled in spaced relationship to preselected interior surface portions of each of said overlapping wing members, a first of said pair of wing members spaced a preselected distance from the other of said pair of wing members and said pair of wing members defining an open bottom burner cavity; means for moving each of said wing members laterally of the other of said wing members to change the volume of said burner cavity; and means for generating thermal energy in said burner cavity, and means for conducting air along at least one of said pair of wing members and into said burner cavity through said preselected distance between said wing members to cool said at least one wing member and to prevent upflow of gases from said burner cavity through said preselected distance.

12. In combination: a stationary frame member; a movable intermediate frame member; means for supporting said intermediate frame from said stationary frame and comprising a pair of bell crank means pivotally coupled to said stationary frame member in spaced relationship, each of said pair of hell crank means comprising a first arm and a second arm and a link member pivotally coupled to said first arm and to said intermediate frame; first actuator means coupled to said stationary frame and to the second arm of a first of said pair of bell crank means; second actuator means coupled to said stationary frame and to the second arm of the second of said pair of hell crank means whereby disjunctive operation of said first and said second actuator means rotates said intermediate frame relative to said stationaryframe and conjunctive operation of said first and said second actuator means provided reciprocal movement of said intermediate frame in a vertical plane relative to said stationary frame; an expandable hood means having walls defining a burner cavity coupled to intermediate frame and adapted to rotate and reciprocate therewith; and means for generating thermal energy in said burner cavity.

13. In combination: a stationary frame member; a movable intermediate frame member; means for movably supporting said intermediate frame from said stationary frame and comprising a pair of bell crank means pivotally coupled to said stationary frame member in spaced relationship, each of said pair of bell crank means comprising a first arm and a second arm and a link member pivotally coupled to said first arm and to said intermediate frame; first actuator means coupledto said stationary frame and to the second arm of a first of said pair of bell crank means; second actuator means coupled to said stationary frame and to the second arm of the second of said pair of hell crank means whereby disjunctive operation of said first and said second actuator means rotates said intermediate frame relative to said stationary frame and conjunctive operation of said first and said second actuator means provides reciprocal movement of said intermediate frame in a vertical plane relative to said stationary frame; a first and a second hood wing member slidingly coupled to said intermediate frame; means for moving said first and said second hood wing members laterally of said 24 intermediate frame; and means for generating thermal energy in said burner cavity.

14. In combination: a stationary frame member; a movable intermediate frame member; means for movably supporting said intermediate frame from said stationary frame and comprising a pair of bell crank means pivotally coupled to said stationary frame member in spaced relationship, each of said pair of bell crank means comprising a first arm and a second arm and a link member pivotally coupled to said first arm and to said intermediate frame; first actuator means coupled to said stationary frame and to the second arm of a first of said pair of bell crank means; second actuator means coupled to said stationary frame and to the. second arm of the second of said pair of bell crank means whereby disjunctive operation of said first and said second actuator means rotates said intermediate frame relative'to said stationary frame and conjunctive operation of said first and said second actuator means provides reciprocal movement of said intermediate frame in a vertical plane relative to said stationary frame; a pair of movable hood wing members, each of said hood wing members comprising a top portion, a downwardlydepending side wall portion coupled to an outer edge of said top portion, a downwardly-depending back portion coupled to a rear edge of said top portion and to said side wall portion, and a plurality of movable burner plates pivotally coupled to a forward edge of said top portion on at least one of said hood wing members and a refractory material coupled in spaced relationship to preselected interior surface portions of each of said hood wing members; track means coupled to exterior surface portions of the top portion of each of said pair of hood wing members; suspension means coupled to said intermediate frame and having wheel members engaging said track means on said pair of hood wing members; means for moving each one of said pair of hood wing members laterally of said intermediate frame on said suspension means; means for coupling said pair of hood wing members together; means for unitarily moving said coupled pair of hood wing members laterally of said intermediate frame; andmeans for generating thermal energy in burner cavity.

15. In combination: a stationary frame member; a movable intermediate frame member; means for movably supporting said intermediate frame from said stationary frame and comprising a pair of bell crank means pivotally coupled to said stationary frame member in spaced relationship, each of said pair of bell crank means comprising a first arm and a second arm and a link member pivotally coupled to said first arm and to said intermediate frame; first actuator means coupled to said stationary frame and to the second arm of a first of said pair of bell chank means; second actuator means coupled to said stationary frame and to the second arm of the second of said pair of bell crank means whereby disjunctive operation of said first and said second actuator means rotates said intermediate frame relative to said stationary frame and conjunctive operation of said first and said second actuator means provides reciprocal movement of said intermediate frame in a vertical plane relative to said stationary frame; a pair of hood wing members each of said hood Wing members comprising a top portion, a downwardly-depending side wall portion coupled to an outer edge of said top portion, a downwardly and rearwardly-depending back portion coupled to a rear edge of said top portion and to said side Wall portion, and a plurality of movable burner plates pivotally coupled to a forward edge of said top portion, and a refractory material coupled in spaced relationship to preselected interior surface portions of each of said hood Wing members; a hood body member spaced apart from said interior portions of said pair of hood wing members, said hood body member having a center portion and the exterior edges of said center portion spaced from said side portions of said pair of hood wing members and defining a gap there= between, downwardly and rearwardly-extending back portion coupled to a rear edge of said center portion, and a plurality of burner port plates coupled to a forward edge of said top portion of said hood body member, and a refractory material coupled in spaced relationship to preselected interior surface portions of said hood body member, said hood wing members and said hood body member defining an open bottomed burner cavity; track means coupled to exterior surface portions of the top portion of each of said pair of hood wing members; suspension means coupled to said intermediate frame and having wheel members engaging said track means on said pair of hood wing members; means for slidingly supporting said hood body member from at least one of said hood wing members; means for moving each one of said pair of hood wing members laterally of said intermediate frame on said suspension means and laterally of said hood body member to change the volume of said burner cavity; means for coupling said pair of hood wing members to said hood body member; means for unitarily moving said coupled pair of hood wing members and said hood body member laterally of said intermediate frame; means for generating thermal energy in said burner cavity, and means for conducting air along said center portion of said body member and into said burner cavity through said gap between exterior edge portions of said center portion and said side portions of said wing members substantially throughout the length thereof for convectively cooling said center portion and preventing upflow of gases from said burner cavity in said preselected distance.

16. In combination: a stationary frame member; a movable intermediate frame member means for movably supporting said intermediate frame from said stationary frame and comprising a pair of hell crank means pivotally coupled to said stationary frame member in spaced rela tionship, each of said pair of bell crank means comprising a first arm and a second arm and a link member pivotally coupled to said first arm and to said intermediate frame; first actuator means coupled to said stationary frame and to the second arm of a first of said pair of bell crank means; second actuator means coupled to said stationary frame and to the second arm of the second of said pair of bell crank means whereby disjunctive operation of said first and said second actuator means rotates said intermediate frame relative to said stationary frame and conjunctive operation of said first and said second actuator means provides reciprocal movement of said intermediate frame in a vertical plane relative to said stationary frame; a pair of overlapping wing members, each of said pair of overlapping wing members comprising a substantially horizontally-disposed top portion, a downwardly-depending side wall portion coupled to an external edge of said top portion, a downwardly and rearwardly-depending rear portion coupled to a rear edge of said center portion and to said side portion, a plurality of movable burner port plates pivotally coupled to a forward edge of said center portion, of at least one of said hood wing members and a refractory material coupled to preselected interior surface portions of each of said overlapping wing members, a first of said pair of wing members spaced a preselected distance from the other of said pair of Wing members and said pair of wing members defining an open bottom burner cavity; track means coupled to exterior surface portions of said top portion of said pair of wing members; support means coupled to said intermediate frame and having wheels engaging said track means on said top portion of said wing members for slidingly supporting said pair of wing members from said intermediate frame; motion producing means for slidingly moving each of said pair of wing members laterally of said intermediate frame member on said support means to change the volume of said burner cavity; means for unitarily moving said pair of wing means laterally of said intermediate frame member; and means for generating thermal energy in said burner cavity, and means for conducting air along at least one of said pair of Wing members and into said burner cavity through said preselected distance between said wing members to cool said at least one wing member and to prevent upfiow of gases from said burner cavity through said preselected distance.

17. In combination: a frame member; an intermediate frame movably coupled to said frame member for vertical relative movement with respect to said frame member; motion producing means coupled to said frame member and said intermediate frame for vertically moving said intermediate frame with respect to said frame member; a body member having a center portion, a downwardly and rearwardly-depending rear portion coupled to a rear edge of said center portion, a plurality of downwardlydepending burner plates coupled to a forward edge of said center portion and a heat resistant material coupled to preselected interior surface portions of said body member; a pair of spaced wing members slidingly supported from said intermediate frame in spaced-apart relationship from exterior surf-ace portions of said body member and each of said wing members comprising a top portion spaced from exterior surfaces of said center portion of said body member and substantially coextensive in length therewith and less than one-half the width thereof; a downwardlydepending side portion coupled to an external edge of said top portion and substantially coextensive in length therewith and spaced from exterior edge portions of said center portion of said body member, and defining a gap therebetween, a downwardly-depending rear portion coupled to a rear edge of said top portion and to said side portion and spaced apart from exterior portions of said rear portion of said body member, and a plurality of movable burner port plates pivotally coupled to a forward edge of said top portion and each of said movable burner port plates adapted to be selectively pivoted upwardly to clear said plurality of burner port plates coupled to said center portion of said body member and a heat resistant material coupled to preselected interior surface portions of each of said wing members; said body member and said pair of wing members defining an open bottom burner cavity; laterally positioned track means coupled to exterior surface portions of said top portion of each of said wing members and said track means on at least one of said wing members having interior track portions spaced from said center section; support means coupled to the exterior surface of said center portion of said body member intermediate said wing members and having wheel members engaging said interior track portions of said track means on said at least one of said wing members for slidingly supporting said body member from said at least one of said wing members; means for slidingly moving each of said pair of wing members laterally of said body member and said intermediate frame to increase and decrease the volume of said burner cavity; means mounted adjacent said plurality of burner plates and said plurality of movable burner port plates for injecting therethro-ugh a combustible mixture of fuel and air into said burner cavity to generate thermal energy therein; means for selectively terminating the injection of fuel and air through said plurality of movable burner port plates; means for coupling said hood wing members to said body member; means for uni-tarily moving said coupled wing members and said body member laterally of said intermediate frame; and means for conducting air along said center portion of said body member and into said burner cavity through said gap between exterior edge portions of said center portion and said side portions of said wing members substantially throughout the length thereof for convectively cooling said center portion and preventing upflow of gases from said burner cavity.

18. A mobile surface heater comprising, in combination: a frame member; a first pair of support wheels coupled to a forward end of said frame member; means for driving said first pair of support wheels; a second pair of support wheels coupled to a rear end of said stationary frame member; means for pivoting each of said second 

1. A SURFACE HEATER COMPRISING IN COMBINATION: A FRAME MEMBER; SUPPORTING WHEELS COUPLED TO SAID MEMBER; AN INTERMEDIATE FRAME MOVABLY COUPLED TO SAID FRAME MEMBER FOR RELATIVE VERTICAL MOVEMENT WITH RESPECT TO SAID FRAME MEMBER; MOTION PRODUCING MEANS COUPLED TO SAID FRAME MEMBER AND SAID INTERMEDIATE FRAME FOR VERTICALLY MOVING SAID INTERMEDIATE FRAME WITH RESPECT TO SAID FRAME MEMBER; A PAIR OF HOOD WING MEMBERS, SLIDINGLY SUPPORTED FROM SAID INTERMEDIATE FRAME MEMBER AND EACH OF SAID HOOD WING MEMBERS COMPRISING A TOP PORTION, A DOWNWARDLY-DEPENDING SIDE WALL PORTION COUPLED TO AN OUTER EDGE OF SAID TOP PORTION, AND A DOWNWARDLY-DEPENDING BACK PORTION COUPLED TO A REAR EDGE OF SAID TOP PORTION AND A REAR EDGE OF SAID SIDE WALL PORTION, AND AT LEAST ONE OF SAID PAIR OF HOOD WING MEMBERS HAVING A PLURALITY OF MOVABLE BURNER PLATES PIVOTALLY COUPLED TO A FORWARD EDGE OF SAID TOP PORTION, AND A HEAT RESISTANT MATERIAL COUPLED TO PRESELECTED INTERIOR SURFACE PORTIONS OF EACH OF SAID HOOD WING MEMBERS, SAID PAIR OF HOOD WING MEMBERS DEFINING A VOLUME COMPRISING AT LEAST PART OF A BURNER CAVITY; MEANS FOR SLIDINGLY MOVING SAID PAIR OF HOOD WING MEMBERS LATERALLY OF SAID INTERMEDIATE FRAME TO SELECTIVELY INCREASE AND DECREASE THE VOLUME DEFINED BY SAID PAIR OF HOOD WING MEMBERS AND TO SHIFT SAID PAIR OF HOOD WING MEMBERS LATERALLY OF SAID INTERMEDIATE FRAME; AND MEANS FOR GENERATING THERMAL ENERGY IN SAID VOLUME DEFINED BY SAID PAIR OF HOOD WING MEMBERS. 